Such watches are fitted with an element that vibrates via the action of a hammer, and thus produces, directly or indirectly, an acoustic wave, via another part. The vibrating element may be a bell, a gong or an element of the type disclosed in EP Patent No. 0 400 205. The bell is voluminous and solid. The same is true of the element disclosed in EP Patent No. 0400 205, formed of a solid rigid crown, mounted on a flexible securing element including two arms, the ends of which are secured to a support. The gong, which is small and compact, is generally preferred. The gong is generally formed of a metal strand of circular cross-section, or of a metal strip, forming a winding whose length is variable depending upon the desired tonality. Secured to the bottom plate via one of its ends, the gong transmits vibrations to the bottom plate, which itself can emit an acoustic wave. Consequently, the quality of coupling between the gong and the bottom plate plays an important role as regards the acoustic power transmitted and the sound quality.
In the case of gongs of large length, such as the gongs fitted to pocket watches, or “cathedral” type gongs, which correspond to two turns around the bottom plate, the gong vibration amplitude can be significant. It sometimes happens that the gong enters into contact with the bottom plate, the middle part or the hammers, which denatures the sound produced. This contact can also occur via the effect of a shock and, in such case, the gong vibrates unexpectedly, thus being able to generate an unexpected and disagreeable sound.
The present invention overcomes these drawbacks by proposing a watch with a striking work fitted with a gong whose vibration amplitude is limited so as to prevent any contact between the gong and a neighbouring part, and thus coupling with the bottom plate is improved.